I think others have given sensible answers here. I liked nycindie's suggestion that you might be picking up on somebody else' sadness, and RedPepper's advice not to worry. And I certainly don't want to deflect from those sound comments. But a couple of "off the wall" ideas came to me, and you might be willing to consider them.
1) I believe in ESP. My grandmother had it pretty strong, and I had it until it freaked me out (getting depressed BEFORE somebody close to me died - without warning) and blocked it out. Later, I decided that I'd thrown away a gift and cultivated it again, so that I got to the point where I could sometimes feel my girlfriend's moods... when she was over 1000km away.
Things might seem fine on the surface, but you might be picking up undercurrents (who knows? maybe even of future problems).
2) One of my sisters used to go wild about her uncouth brothers chewing food with our mouths open. The sound sickened her. Later (as an adult, and through some kind of therapy) she came to realise the basis of this revulsion.
It seems that when very young, she used to wake up at night and go down the hallway to our parents' bedroom, where she'd get into bed with them. On occasions, the door would be locked, she'd feel rejected... and she'd hear these sounds from inside the bedroom that sounded much like the sounds someone makes when they chew with an open mouth. Slurp slurp, smatch smatch.
Once she made this connection - that the sounds reminded her subconsciously of her earlier feelings of rejection - she was never troubled by them again.
I apologise if I've muddied the waters, but if there's any chance that either of those 2 points helps...
If I can't dance, I want no part in your Revolution.
- Emma Goldman Anarchist and Polyamorous par excellenceThe person who says something is impossible should not interrupt the person who is doing it.
- old Chinese proverbAnd the day came when the risk to remain tight in a bud was more painful than the risk it took to blossom.
~ Anais NinI'd rather have a broken heart / Than have a heart of stone.